The arrests were made during raids that began on July 22, in which police say they also rescued 20 underage women.

Dozens of bars and hotels in the city centre were searched for missing people, authorities said.

Ciudad Juarez - on the border with the US - is one of the most violent places in the country.

The city saw more than 3,000 murders in 2010, making it by far Mexico's deadliest city.

But human rights groups have often drawn attention to the disappearance of young women in the area.

Analysts say that much of the violence in Mexico, particularly in the north, is linked to the trade in drugs and humans.